The present invention relates to an elevator device for an abdominal wall, in videolaparoscopic surgical operations, of the type comprising mechanical elements for tensioning the abdominal wall, and movement means engaging said mechanical elements.
It is known that in the surgery field there is a mini-invasive operative method availing itself of the so-called "laparoscopy" or "videolaparoscopy", which enables operations in the abdominal cavity to be executed without causing serious traumas.
Presently, this type of surgery is for example used for extirpation of cholecyst, ovarian cysts, removal of inguinal hernia, operations of various types on colon, lever and bile-ducts, and peritoneum.
According to said operative method, the abdominal wall is provided to be raised so as to form an appropriate work chamber, into this chamber being then introduced through holes, both instruments enabling an endoscopic visualization of the peritoneal cavity and instruments enabling a surgical operation.
In order to form this chamber, the method of injecting carbon dioxide or another gas into the peritoneal cavity, to create the so-called "pneumoperitoneum" has been known for a long time. Peritoneum, as well-known, is a serous membrane enveloping the abdominal viscera and partly the pelvic cavity.
This method has many contraindications.
In fact, isolated accidents such as perforation of the intraabdominal viscera and relevant blood vessels are possible; there are inconveniences connected with dissolution of carbon dioxide in the human organism, such as for example modification of the blood pH which gives rise to acidosis, and release of catecholamines is possible, which results in intra-operative hypertensive crises.
In addition, injection of gas makes it difficult to operate on patients suffering from cardiopathy, as they hardly tolerate an increase in the intraabdominal pressure, and increases post-operative pains, so that the patients' stay in hospital becomes longer.
Then other time-consuming operations may be necessary, such as previous washings of the peritoneal cavity and in addition, while the operation is taking place, fumes produced by the radio knife during the cutting and coagulation steps cannot be sucked, in order not to suck the carbon dioxide too therewith.
Also required is the use of particular and expensive cannulas, of the so-called "trocars" type provided with a dual valve, and also of special instruments, to avoid escape of the injected gas.
Attempts have been made to solve the above drawbacks by the use of raising methods no longer based on the injection of carbon dioxide or other gases into the abdominal cavity, but based on devices including mechanical tensioning elements that are inserted into the abdomen, and movement means capable of lifting these elements so as to form said work chamber for videolaparoscopic surgical operations.
The insertion of metal wires into the abdomen is for example known, said wires being maintained raised by chains, threads or handles vertically overlying each metal wire and penetrating the patient at both ends of each metal wire. Also known is the solution providing the introduction into the peritoneal cavity of two blades or bars pivoted on each other at one end. The two blades are kept close to each other when they are introduced into the peritoneal cavity through a single hole and are then compass-wise spaced apart from each other and then vertically raised.
Up to now these methods have not given satisfactory results. Actually, the above methods have avoided the "pneumoperitoneum", but have shown both the drawback of the so-called "tent effect" that greatly reduces the space at the surgeon's disposal, and the drawback of an important traumatism. Said "tent effect" consists in that the raised abdomen portion and the immediately surrounding portions tend to bend downwardly like the walls of a tent, thereby reducing visibility and the available operative space.
As regards traumatism, it is caused by the great invasive action of the mechanical tensioning elements introduced into the peritoneal cavity.
In fact, stresses transmitted to the abdominal tissues are not distributed and at some areas stress concentrations occur which can give rise to traumas to the tissues.
Practically, in order to avoid these traumas it is necessary to renounce all attempts of achieving a wide elevation of the abdominal wall.
It should be also noted that raising of the abdominal wall needs great efforts that give rise to big local deformations in the mechanical tensioning elements which cannot be bulky. These deformations may bring about further risks of traumas or local tissue injuries and in addition reduce the width of the work chamber.